NRL Set to Launch Experimental TacSat-4 Spacecraft

August 22, 2011 09:24 AM Eastern Daylight Time

WASHINGTON--(BUSINESS WIRE)--The Naval Research Laboratory’s Tactical Satellite IV (TacSat-4) is
scheduled to launch from the Alaska Aerospace Corporation’s Kodiak
Launch Complex, Tuesday, September 27, 2011, aboard an Orbital Sciences
Corporation Minotaur-IV+ launch vehicle. The Office of Naval Research
(ONR) sponsored the development of the payload and the first year of
operations. The Operationally Responsive Space (ORS) Office funded the
launch which is managed by the Space Development and Test Directorate
(SD), a directorate of the Air Force Space and Missile Systems Center
(SMC).

Shortly after launch, the TacSat-4 spacecraft will be deployed into a
unique, highly elliptical orbit with an apogee of 12,050 kilometers.
This orbit helps augment current geosynchronous satellite communication
by including high latitudes.

TacSat-4 is a Navy-led joint mission which provides 10 Ultra High
Frequency (UHF) channels and allows troops using existing radios to
communicate on-the-move (COTM) from obscured regions without the need
for dangerous antenna positioning and pointing.

"Communication is a critical warfighting requirement. TacSat-4 will
support forward deployed forces at sea and Marines on the ground," said
Dr. Larry Schuette, ONR’s director of innovation.

“We've developed a technology more rapidly and at lower cost that will
supplement traditional satellites, giving multiple combatant commanders
around the globe another outlet for data transmission and communications
on the move.”

TacSat-4 provides flexible up and down channel assignments, which
increase the ability to operate in busy radio-frequency environments and
will cover the high latitudes and mountainous areas where users
currently cannot access UHF satellite communications (SATCOMs). The NRL
Blossom Point Ground Station provides the command and control for
TacSat-4. The Virtual Mission Operations Center (VMOC) mission planning
system allows dynamic reallocation to different theaters worldwide that
enables rapid SATCOM augmentation when unexpected operations or natural
events occur.

Marking the 100th launching of an NRL built satellite into orbit,
TacSat-4 is an experimental spacecraft that will test advances in
several technologies and SATCOM techniques. Ultimately, TacSat-4 will
augment the existing fleet by giving the SATCOM Support Centers (SSC) an
additional space asset to provide communications to otherwise
under-served users and areas that either do not have high enough
priority or do not have satellite visibility. The project helps define
future options for launching one or more smaller, highly elliptical
orbit (HEO) satellites allowing the military to achieve the benefits of
a combined HEO and geosynchronous orbit constellation.

The spacecraft bus was built by NRL and Johns Hopkins University Applied
Physics Laboratory (APL) to mature ORS bus standards. It was developed
by an Integrated (government and industry) System Engineering Team, the
“ISET Team,” with active representation from AeroAstro, Air Force
Research Laboratory, Johns Hopkins Laboratory APL, ATK Space, Ball
Aerospace and Technologies, Boeing, Design Net Engineering, General
Dynamics AIS, Microcosm, Microsat Systems Inc., Massachusetts Institute
of Technology Lincoln Laboratory, Orbital Sciences, NRL, SMC, Space
System Loral, and Raytheon. The Office of the Director of Defense
Research and Engineering (DDR&E) funded the standardized spacecraft bus.

TacSat-4 is managed by the Naval Research Laboratory Naval Center for
Space Technology.

The Naval Research Laboratory is the Department of the Navy's corporate
laboratory. NRL conducts a broad program of scientific research,
technology, and advanced development. The Laboratory, with a total
complement of nearly 2,500 personnel, is located in southwest
Washington, D.C., with other major sites at the Stennis Space Center,
Miss., and Monterey, Calif.